Sunday, April 12, 2015

Point Comfort 23- Part 2

The strong back was next, and for this four by twenty four foot structure, we used fir 2 x 8’s. We picked out the best construction grade stock we could find, and jointed one edge of each, then ripped them to a common width.

Jointing an edge of the 2x8's.

Deciding which piece goes where, based on straightness and flatness.

We set up and screwed together the strong back, again squaring the assembly carefully. We then braced the strong back to the trestles with plenty of diagonal bracing so the whole business is rigid, then cut notches in the center of all cross pieces, through which we stretched a taut center string line. this will be used to line up the molds.

Cutting the center line notches. Bracing can be seen here.

Stretch it tight!

We chose particle board for the molds (I hate MDF dust), and I had one team laying out stations from the full-size patterns, and another team cutting the molds with our home-made track saw. This is a chine hull, so all the cuts are straight lines.

Howie and Javier lay out the molds from full size patterns.

Pat Daniels runs the home made track saw.

Hans has taken over here. There were a lot of cuts!

John and Severn are setting up the cross ties.

The layout team was careful to mark the vertical center-line and waterline on both sides of each mold. Even with plenty of help, the molds were an all day project. The next day, we set all the molds up, using a laser to get the waterlines all in the right place, and a four foot level to get them plumb.

Midship mold goes in first.

I don't know what that old man is saying.

I always set up the midship mold first, spending the time to get it right and braced securely. We screwed 2 x 2’s across the strong back on the stations, then shimmed the molds to the laser and screwed them to the cross spalls.

The mold center line aligns with the string line on the strongback, and a laser is set to the comm DWL height.

The molds are braced securely!

Pat, Jim, and Hans.

Each subsequent mold was braced back to the midship mold, and held the correct distance apart, 36” in this case. When the molds were set up, we couldn't resist springing a batten around the sheer and chine, to get a sense of the hull shape.

That’s where we are now. We have to cut out the stem, and fabricate the transom next, before setting up the permanent longitudinals. Stay tuned!